Palaeoglandina turolensis, Albesa & Neubauer, 2023

Albesa, Joaquín & Neubauer, Thomas A., 2023, Shifting shell morphology in a Late Miocene-Pliocene land snail species lineage (Gastropoda: Stylommatophora: Spiraxidae), with the description of a new species, Geodiversitas 45 (21), pp. 643-657 : 648-651

Palaeoglandina turolensis n. sp.

( Figs 4 A-O; 5A-O; 6G)

urn:lsid:zoobank.org:act:F8861172-2398-45C4-AEC6-21143593A1AA

Glandina antiqua – Vilanova I Piera 1863: pl. 2, fig. 26 [non Klein, 1852].

Glandina inflata – Dereims 1898: 175, 179 [non E.von Martens, 1891].

Glandina aquensis var. obtusa – Depéret & Sayn 1900: 108, pl. 1, fig. 77 [non Depéret, 1890]. — Royo Gómez 1922: 136-138, pl. 12, fig. 17a, b [non Depéret, 1890].

Glandina aquensis – Royo Gómez 1922: 136-138, pl. 12, fig. 16a, b [non Klein, 1852]. — Gómez Llueca 1931: 57, pl. 51, figs 14-17 [non Klein, 1852].

DIAGNOSIS. — Large oval to fusiform shell, with SH/SW ratio ranging between 1.63-2.05, and with up to 3.9 smoothly to moderately convex whorls separated by shallow sutures. Short spire constituting 10-15% of the total shell height. Protoconch up to 1.9 whorls, ornamented by deep spiral groove flanked by thick, short, prosocyrt riblets towards the beginning of the shell. Large last whorl constituting about 85-90% of total shell height. Large, pyriform and often flattened aperture on palatal margin, corresponding to almost 60% of total shell height; outer lip thin, sharp, non-reflexed, mostly subvertical, angular at its adapical limit, strongly curved at base.

TYPE MATERIAL. — Holotype. MAP-8405: SH: 38.2 mm; SW: 19.1 mm. — Paratypes. MAP-8406: SH: 36.2 mm; SW: 18.0 mm. MAP-8407: SH: 39.5 mm; SW: 20.9 mm. MAP-8408: SH: 32.9 mm; SW: 16.7 mm. MAP-8409: SH: 33.9 mm; SW: 18.6 mm. MAP-8410: SH: 31.8 mm; SW: 15.5 mm. MAP-8411: SH: 31.0 mm; SW: 15.4 mm. MAP-8412: SH: 34.5 mm; SW: 17.2 mm. MAP-8413: SH: 32.2 mm; SW: 15.9 mm. MAP-8414: SH: 31.9 mm; SW: 16.0 mm.

ADDITIONAL MATERIAL. — MAP-8415: SH: 32.9 mm; SW: 16.4 mm. MAP-8416: SH: 33.0 mm; SW: 17.9 mm. MAP-8417: SH: 33.8 mm; SW: 17.3 mm. MAP-8418: SH: 31.2 mm; SW: 16.2 mm MAP-8419: SH: 34.9 mm; SW: 16.6 mm. MAP-8421: SH: 45.6 mm; SW: 24.9 mm; MAP-8422: SH: 42.5 mm; SW: 21.3 mm. MAP-8423: SH: 40.1 mm; SW: 21.4 mm. MAP-8424: SH: 39.4 mm; SW: 20.8 mm; MNCNI-28900-A: SH: 40 mm; SW: 21.2 mm; MNCNI-28900-D: SH: 33.4 mm; SW: 20.5 mm. MNCNI-28900-E: SH: 44.4 mm; SW: 24.9 mm; MNCNI-11300-E: SH: 39.8 mm; SW: 23.8 mm; MVHN-040822JA01: SH: 37.4 mm; SW: 20.4 mm; MVHN-040822JA02: SH: 40.6 mm; SW: 21.7 mm; MGM 118M: SH: 46.1 mm; SW: 24.8 mm. MGM 3732M: SH: 33.1 mm; SW: 19.1 mm. MAP-8420: protoconch.

ETYMOLOGY. — In reference to the Teruel Basin, where the species is described from.

TYPE HORIZON. — Marls of Lower Pliocene age (Zanclean, lower Ruscinian, Neogene mammal zone MN 14) rich in organic matter, with variable shades between grey-brown and purple and with frequent whitish carbonate nodulations, as well as local accumulations of iron oxides/carbonates ( Albesa et al. 1997).

TYPE LOCALITY. — La Gloria 4 (Teruel, Spain) (40°20’48.5”N, 1°04’01.9”W).

STRATIGRAPHIC AND GEOGRAPHIC DISTRIBUTION. — This species is recorded from the late Tortonian (Turolian, MN12, 7.87 Ma) and Zanclean (Ruscinian, MN14, 4.4-4.54 Ma) of the Teruel Basin ( Royo Gómez 1922; Gómez Llueca 1931; this study).

DESCRIPTION

Large oval to fusiform shell with up to 3.9 smooth to moderately convex whorls separated by shallow, often slightly indented sutures. Short spire consisting of up to 2.9 whorls and accounting for 10-15% of total shell height; obtuse apex. Shell shape, particularly spire height and SH/SW ratio, varies considerably among assemblages ( Table 1 ; see also Fig. 3 ). Protoconch up to 1.9 whorls, with nucleus smooth and remaining portion ornamented by deep spiral groove located at approximately one third below upper suture and flanked by thick, short, prosocyrt riblets, creating altogether a pattern remotely resembling a fern pinna with pinnules. Passage into teleoconch marked by irregularly shaped scar and onset of growth lines. Teleoconch formed by 2 whorls. Teleoconch ornamentation consists of strong and numerous growth lines, weakly prosocline to almost orthocline, crossed by fine, almost imperceptible spiral grooves, which give rise to weak reticulation. Large last whorl, about 85-90% of total shell height. Large aperture constituting almost 60 % of total shell height; pyriform, acuminate at suture and rounded at base, often flattened at palatal edge and provided with wellmarked notch at boundary between columellar and basal edges; peristome simple with columellar edge arched and forming callosity which is obliquely truncated at base; outer lip thin, sharp, not reflexed, mostly subvertical, often adapically thickened and strongly curved at base. Not umbilicate.

REMARKS

Of the 23 species of Palaeoglandina currently recognized, the majority (18) come from Lower Eocene (Ypresian) to Middle Miocene (Langhian) deposits (e.g. Wenz 1923; Truc 1971; Le Renard & Pacaud 1995; Binder 2004; Harzhauser et al. 2014a,b; Höltke & Rasser 2017; Höltke et al. 2018; MolluscaBase 2023). Only five species have been recorded from the Late Miocene (Tortonian) to the Late Pliocene (Piacenzian)/ Early Pleistocene (Calabrian) (e.g. Wenz 1923; Esu et al. 1993; Gliozzi et al. 1997; Montenat & Truc 1971; Montoya et al. 1999a, b, 2001; MolluscaBase 2023) and thus fall in a similar stratigraphic range as Palaeoglandina turolensis n. sp.

Two species have been located in supposedly Late Miocene sites, i.e. Palaeoglandina aquensis ( Matheron, 1843) , originally described from the Burdigalian of Aix-en-Provence (Bouches-du-Rhône, France; Esu 1999) but also cited from Tortonian strata (e.g. Schlosser 1907; Royo Gómez 1922), and P. galloprovincialis ( Matheron, 1843) , described from the Tortonian (?) of Peyrolles (Bouches-du-Rhône, France). (Note that the age of the deposits at Peyrolles is uncertain; it was indicated as “Pontien” by Wenz (1923), while species recorded from that site were attributed to both the Early Miocene (mammal stage MN4) and the Late Miocene (MN8) by Esu 1999). The possible syntype series of both species have been located in the MHNM. Since the entire Matheron collection is deposited in the MHNM (C. Borrely pers. comm.), both the specimens of P. aquensis from Aix and those of P. galloprovincialis from Peyrolles could be the ones used by Matheron to describe the two species and thus belong to the type series. We examined two specimens whose measurements are similar to those given by Matheron ( P. aquensis : MHNM 6034.9314.1, Fig. 6A; P .galloprovincialis: MHNM 6034.9317.1, Fig. 6B ). However, none of the specimens match the figures of Matheron (1843: pl. 34, figs 8, 9; pl. 34, fig. 18), so we refrain from designating lectotypes until the material can be studied in greater detail. Among the above-mentioned records of P. aquensis in the Iberian Peninsula, only the specimens from the Teruel Basin have been located. Palaeoglandina turolensis n. sp., besides being much younger, clearly differs from P. aquensis in its shell morphology. Palaeoglandina aquensis has, according to the description, figures and measurements provided by Matheron (1843: 279, pl. 34, figs 8, 9), a SH/ SW ratio greater than 2 ( Fig. 6A ; Table 1 ), as well as a less obtuse spire and a proportionally lower last whorl than the new species from Teruel, whose SH/SW ratio is on average less than 2 ( Table 1 ) and has a more convex shell. Depéret (1890) described P. aquensis var. obtusa for specimens from the Pliocene of Roussillon with a slightly more obtuse spire and slightly more convex morphology. This author also indicated the possibility that the new variety is the same as Palaeoglandina porrecta ( Gobanz, 1854) from the Miocene of the Styrian Basin ( Austria). However, although we have not been able to locate specimens from Roussillon and the work by Depéret (1890) does not contain associated figures, we think that P. aquensis var. obtusa is different from P. porrecta , a species found only in Middle Miocene sites ( Harzhauser et al. 2014b; Höltke & Rasser 2017). Besides the age difference, according to the description and figure of Gobanz (1854: 196, fig. 5), P. porrecta is characterised by a sharp ovate-elongate aperture that attains 70% of the total shell height according to the measurements indicated by Gobanz (1854), as well as an elongate, regularly convex last whorl. Note, however, that P. porrecta is currently considered a taxon inquirendum, since the type series is lost, and the limited available material is inconclusive ( Harzhauser et al. 2014b). Depéret & Sayn (1900) listed the variety from Ratavoux (Cucuron, Vaucluse, France), dated, like Los Aljezares, to the Middle Turolian (MN12) ( Ballesio et al. 1979; Esu 1999; Ménouret 2014). Our new species bears a strong resemblance to those from Ratavoux figured by Depéret & Sayn (1900: pl. 1, fig. 77) and those deposited at CERESE (UCBL-FSL 148027, Fig. 6D 1-D 2 ), all having a characteristic, convex shape. However, the degree of preservation of the French material makes a precise comparison difficult. Palaeoglandina turolensis n. sp. has a characteristic ornamentation on the protoconch not observed in any of the other European species we investigated, i.e. Palaeoglandina gracilis (Zieten, 1832) ( Fig. 6H ), P. dactylina Binder, 2004 ( Binder 2004, Fig. 6b ) and P. taurinensis ( Sacco, 1886) ( Fig. 6I ). This ornamentation could be a diagnostic character, but the absence of an apex in the specimens of P. aquensis var. obtusa deposited at CERESE prevents us from studying it and comparing it with that of the new species. The strong resemblance between the Ratavoux and Los Aljezares specimens, supported by similar age, suggest that they may be conspecific taxa, but the state of preservation of the French specimens does not allow a final conclusion. If both taxa turn out to be synonymous, the name turolensis still has priority, since Glandina aquensis var. obtusa Depéret, 1890 is a junior homonym of Glandina obtusa Pfeiffer, 1845 .

Regarding P. galloprovincialis ( Fig. 6B ), according to Matheron’s description and the measurements he provided ( Matheron 1843: 279, pl. 34, fig. 10), the species has, with a much higher SH/SW ratio than the new species, a more slender appearance.

Three species of the genus Palaeoglandina are currently recognised in the European Pliocene: P. paladilhei ( Michaud, 1877) , from the Early Pliocene (MN14) of Hauterives ( France); P. lunensis (D’Ancona in Cocchi, 1867), from the Italian Late Pliocene to Early Pleistocene (MN16-MN17) ( Esu 1999; Ciangherotti et al. 2007) and P. montenati Truc, 1971 from the Late Pliocene (MN16) and Early Pleistocene (MN17) of Alicante and Murcia ( Montenat & Truc 1971; Montoya et al. 1999a,b, 2001).

Palaeoglandina paladilhei is a problematic species described from incomplete fragments of several specimens “three fragments, two of which show the last whorl and leave the opening fairly complete and the third comprising the apex” ( Michaud 1877: 7), whose reconstruction was considered “unsatisfactory” by Montenat & Truc (1971: 57). Although the reconstruction is indeed problematic and, in our opinion, shows one whorl too many, the fragments of the apical part of the shell and of the last whorl with the opening are drawn in great detail and are easily distinguishable from the inferred intermediate part. According to this information and the original description, P. paladilhei is very different from P. turolensis n. sp., easily distinguished by the shape of the first whorls, flat in the Hauterives species and rounded in the new species, as well as by the shape of the last whorl and the aperture, narrower and more elongated in the French species.

Palaeoglandina lunensis , which has been figured and described in detail by De Stefani (1880), has a regularly fusiform shell with low-convex whorls and, with one more whorl, a slower growth. Moreover, the Italian species appears to have a very marked reticulate ornamentation of teleoconch ( De Stefani 1880: pl. 2, fig. 13), which is not seen in P. turolensis n. sp. where the reticulation observed is very faint.

Palaeoglandina montenati , a large species with a total height of c. 60-70 mm (holotype, UCBL-FSL 98969: 59.5 mm; paratype, UCBL-FSL 98971: 69 mm, Montenat & Truc 1971: 57), has a more fusiform morphology ( Montenat & Truc 1971: fig. 4a-c), with a SH/SW ratio of more than 2, a spire that attains about 10% of the total shell height and thus is proportionally shorter than that of the new species and a AH/SH ratio greater than in P. turolensis n. sp. ( Table 1 ). The type specimens are moulds, but the specimens from Quibas are well preserved, showing a proportionally shorter spire with a flatter whorl profile, as well as a last whorl that is also proportionally wider and convex abapically. All this gives the shell a more fusiform morphology than the specimens from the Teruel Basin. On the other hand, the ornamentation of the protoconch is similar to that of P. turolensis n. sp., a circumstance that may indicate the possibility that they belong to the same evolutionary lineage. However, confirming this interpretation will require a more detailed assessment of well preserved specimens of other Palaeoglandina species.

Figures

FIG. 4. — A, Palaeoglandina turolensis n. sp. from La Gloria 4 (Ruscinian, Teruel Basin): A1-A3, MAP-8405, holotype; B, MAP-8406, paratype; C, MAP-8407, paratype; D, MAP-8408, paratype; E, MAP-8409, paratype; F, MAP-8410, paratype; G, MAP-8411, paratype; H, MAP-8412, paratype; I, MAP-8413, paratype; J, MAP-8414, paratype; K, MAP-8415; L, MAP-8416; M, MAP-8417; N, MAP-8418; O, MAP-8419. Scale bar: 10 mm.

FIG. 3. — Results of the morphometric analyses: A, principal components analysis of the Procrustes shape coordinates; shown are the first three axes explaining 88.5% of the total variance; B, thin-plate spline deformation grid illustrating the extreme values for each principal component; deformations were magnified to a factor of 2 to highlight variation of distinct traits; C, reconstructed mean shapes for all material as well as across specimens for each locality.

FIG. 6. — A, Palaeoglandina aquensis (Matheron,1843) from Aix (Burdigalian,Aix Basin),MHNM 6034.9314.1;B, P. galloprovincialis (Matheron, 1843) from Peyrolles (Tortonian, Durance Basin), MHNM 6034.9317.1; C1, C2, P. montenati Truc, 1971 from Quibas (Calabrian, Quibas site), MVHN-180222GM05;D1, D2, P. aquensis var. obtusa (Depéret, 1890), UCBL-FSL 148027; E1, E2, P. gracilis (Zieten, 1832), NHMW 2013/0572/0040; F1, F2, P. taurinensis (Sacco, 1886), BS.093.02.001; G, P. turolensis n. sp., MAP-8420, detail of protoconch; H, P. gracilis (Zieten, 1832), NHMW 2013/0572/0040, detail of protoconch; I, P. taurinensis (Sacco, 1886), BS.093.02.001,detail of protoconch;J, P.montenati Truc,1971 from Quibas,MVHN-180222GM05,detail of protoconch.Scale bars:A-F,10 mm;G,1 mm;H-J,2 mm.

FIG. 1. — Geographical and geological overview of the studied sites in the Teruel Basin: A, schematic geological map of the Teruel Basin region indicating the areas in which the studied sites are located (modified after Ezquerro et al. 2022a); B, C, detailed locations of the Los Aljezares (AL), La Gloria 4 (LG4) and Orrios 1 (OR1) sites. Underlying images © Google Maps 2023, CNES/Airbus, Maxar Technologies.

FIG. 2. — A, Shell measurements,following Solem & Climo (1985), and arrangement of landmarks (large circles) and semi-landmarks (small dots). The numbers in parentheses indicate the number of points for each of the two semi-landmark curves. See text for abbreviations. B, Protoconch measurements, following Verduin (1977). Abbreviations: N, nucleus; P/T boundary, protoconch/teleoconch boundary. Scale bar: A, 5 mm; B, 6 mm.